60 Proceedings of the Royal Physical Socvety. 
sporangia is well seen in fig. 1, at the part marked a. The 
oval sporangia (which have thick walls, as indicated by the 
amount of carbon they possess) stand upright on the bracts 
a short distance from their point of attachment to the cone. 
The bracts marked a in fig. 1 are shown enlarged at fig. la. 
A small portion of a stem—that exhibited at 6 in fig. 2, 
and marked with a *, is enlarged at 2a to show the small 
thorn-like points which are irregularly scattered over its 
surface. 
Perfect specimens of verticils of leaves are very rare. Figs. 
3 and 4 show, however, their general structure and appear- 
ance. In the upper example in fig. 4 the leaves are simply 
dichotomous, or sometimes one of the forks divides again. 
In fig. 3 the leaves are either dichotomous, or one fork 
divides again, or both of the arms of the primary fork 
dichotomise. 
In describing this species, Dr Stur mentions Asterophyllites 
trichomatosus and Sphenophyllum trichomatosum, “ Rami 
speciei calamitarum mihi ignote,” and refers to his speci- 
mens as showing the union of Asterophyllites and Spheno- 
phyllum in one and the same plant, from which, according to 
his view, it follows that Calamites had two forms of branches 
—one the generally recognised foliage of Calamites—the 
Asterophyllites, and the other the genus Sphenophyllum ; and 
not only are these two genera the foliage of Calamutes, but 
are both found on the same species of Calamite That this 
conclusion is thoroughly erroneous can be seen by any one 
who cares to study the subject, and it has originated entirely 
from the misinterpretation of his specimens. 
When slabs containing Sphenophyllum are split, a few of 
the verticils of leaves or the leaves themselves are frequently 
broken through in section, while on other verticils the leaves 
may be spread out, or the specimen might be in part badly 
preserved. At 0, fig. 2, is given an example which explains 
these remarks. On the remains of the uppermost verticil of 
leaves is shown a fragment of a leaf which exhibits the 
characteristic dichotomy of the foliage of Sphenophyllum 
trichomatosum. In the second verticil the leaf is either cleft 
1 See Dr Stur’s Restoration, p. 69. 
